<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>

  <body>
    <div id="app">
      <p>请选择你要购买的书籍</p>
      <ul>
        <li v-for="(item,index) in arr">
          {{arr[index].name}} <button @click="arr[index].count++">买书</button>
        </li>
      </ul>
      <table border="1" width="500" cellspacing="0">
        <tr>
          <th>序号</th>
          <th>书名</th>
          <th>单价</th>
          <th>数量</th>
          <th>合计</th>
        </tr>
        <tr v-for="(item,index) in arr">
          <td>{{index+1}}</td>
          <td>{{item.name}}</td>
          <td>{{item.price}}</td>
          <td>{{item.count}}</td>
          <td>{{item.count*item.price}}</td>
        </tr>
      </table>
      <p>总价格为:{{total}}</p>
    </div>
    <script src="./vue.js"></script>
    <script>
      new Vue({
        el: "#app",
        computed: {
          total() {
            return this.arr.reduce((sum, v) => (sum += v.price * v.count), 0)
          },
        },
        data: {
          arr: [
            {
              name: "水浒传",
              price: 107,
              count: 0,
            },
            {
              name: "西游记",
              price: 192,
              count: 0,
            },
            {
              name: "三国演义",
              price: 219,
              count: 0,
            },
            {
              name: "红楼梦",
              price: 178,
              count: 0,
            },
          ],
        },
      })
    </script>
  </body>
</html>
